nescient
unbelieving
Humean
Humist
Pyrrhonic
Pyrrhonist
ambiguous
capricious
chancy
changeable
dicey
distrustful
doubter
doubtful
doubting
doubting Thomas
dubious
dubitante
equivocal
erratic
fickle
from Missouri
hesitant
hesitating
in doubt
incalculable
incredulous
indecisive
indemonstrable
irresolute
leery
mistrustful
mistrusting
polysemous
questioning
scoffer
scrupulous
shy
skeptic
skeptical
suspecting
suspicious
touch-and-go
unaccountable
uncertain
unconfirmable
unconvinced
undivinable
unforeseeable
unpersuaded
unpredictable
unprovable
individual
mortal
person
religious person
somebody
someone
soul
Aristotelian
Darwinian
Marxist
atheist
cynic
empirical
evolutionary
humanist
idealistic
libertarian
materialist
materialistic
mechanistic
pessimist
pragmatic
rationalistic
sceptical
secular
skeptics
socialistic
theistic
utilitarian
caustic
diagnostic